I'm inlined to think that the odds are pretty good we're in a simulation, but I'm also inclined to think for reasons like the ones philosopher David Chalmers gives, it doesn't matter that much. If physicists announced a consensus tomorrow that there's strings at the bottom instead of bosons and fermions, I'd be like, "huh, cool, so that's what we're made of." And Chalmers suggests we should have the same reaction if it's bits at the bottom - "huh, cool, so that's what we're made of."
Though contrary to that, I just remembered some intriguing advice from wacky but smart Robin Hanson about how to live if we are in a simulation.